Answer:
The value of z is 58
Explanation:
The mean is the average of a set of numbers. Mean = (sum of the numbers)/(the number of numbers).
We are told that the mean of x+y+z is = 55.
We can wriote this as:
55 = (x+y+z)/3
We learn that x+y = 107. So lets enter that number for x + y:
55 = (x+y+z)/3
55 = ((x+y)+z)/3
55 = ((107)+z)/3 [Substitution]
55 = (107+z)/3
165 = 107+z [Multiply both sides by 3]
z = 58 [Simplify]
CHECK:
Is the mean of x, y, and z 55?
55 = (x+y+z)/3 ?
55 = ((107)+z)/3 ? [Since we know x+y = 107]
55 = ((107)+58)/3 ? [Since z=58]
55 = (165)/3) ?
55 = 55 YES The value of z is 58